enhance Qt5 compatibility

- replace Q_WS_MAC (not supported anymore in Qt5) with Q_OS_MAC (supported
  in Qt4/5)

src/qt/notificator.h

@@ -61,7 +61,7 @@ private:
     void notifyDBus(Class cls, const QString &title, const QString &text, const QIcon &icon, int millisTimeout);
 #endif
     void notifySystray(Class cls, const QString &title, const QString &text, const QIcon &icon, int millisTimeout);
-#ifdef Q_WS_MAC
+#ifdef Q_OS_MAC
     void notifyGrowl(Class cls, const QString &title, const QString &text, const QIcon &icon);
 #endif
 };